Tem este daqui que acho que ainda não tem aqui no fórum:
The secret of weed
Lamentamos, mas não tem permissão para ver o conteúdo do spoiler.
The weeds generally considered as useless nuisance are proved and shown to be enriching soil in this film. Weeds are worth just to be there growing. They come up in the Spring even though they look withered and dead the previous year. These are the some of the wonderful and mystic scenes as well as pollination and travelling of seeds. Weeds grow in the fields where crops fail to grow, and they can take up heavy metals and cleanse the soil recovering ecological system.
http://www.youtube.com/watch?v=o0CSQ4PIbqA#ws (http://www.youtube.com/watch?v=o0CSQ4PIbqA#ws)